Process of and apparatus for making sheet glass



July 3, 1923. v 1,460,488

W. E, HEAL PROCESS OF AND APPARATUS FOR MAKING SHEET GLASS Filed Jan. 17, 1921" gwbanfroz A .wdwmm Patented July 3, 1923.

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d I PROCESS F AND APPARATUS FR IPIlAKINGrl SHEET GLAS `Application` tiled. January 17, 1921. Serial No. 437,909.

To aZZ lwir/0m it may concern Be it known that I, WILLIAM E. Haai., a citizen of the United States, residing at \Washington, in the District of Columbia, Baye invented certain new and useful-1in` rovements in Processes of and Apparatus or Making Sheet Glass, of which the following is a specification.

This invention relates to processes of and 19 apparatus for making sheet glass, and it comprises a method wherein finished and cooled glass is reduced to a fine and uniforml glass ing then. fused and allowed to cool slowly, and it further comprises an apparatus includinga receptacle for powdered glass, a rod of infusible metal embedded in the glass in said receptacle, means for heating said rod, means for moving said rod through the body of glass, and means for Iremoving the surface of the sheet of glass formed.

`In the present process, finished glass` in a uniformly powdered condition is heated to reduce it to a plastic or molten condition and allowed to fuse. The sheet glass so formed is then cooled and the surface polished to produce a fire polish. In one form of the invention, the powdered glass is arranged on a plate or table constructed of copper or other material permitting of a high polish and placed in a furnace or chamber to permit fusing of the powdered glass. The plate may be constructed tol permit a circulation of water beneath the surface for cooling purposes. The glass to be fused may be arranged on the plate at any desired thickness and heating continued,

'until the entire body of glass is properly fused. f

In another form of the invention, the powdered glass is arranged in a receptacle, and a rod of tantalum, tungsten, molybdenum, or other highly infusible metal is vembedded therein. This rod is connected in an electric circuit, whereby it may be heated to fuse the glass in the 'immediate vicinity.

.method of forming powdered condition, the powderedto the wire 9 by means of branch wires 12,

one form of apparatus, wherein the glass is formed by moving a heated rod upwardly, Figure 2 is a similar View showing a' sheet glass by moving` the rod downwardiy',

Figure 3 is a diagrammatic illustration of the electric circuits employed in practicing the process,

Figure i is a, plan view of another forni of apparatus capable of use in performing the process, and,

Fifrure 5 is a sectional view thereof` Rerierriiig to the drawings, the reference numeral l designates a heating receptacle made of suitable material and adapted to receive a, body 2 of finely divided, powdered glass.` The glass employed in. practicing the process is finished and cooled glass, usually called cullet. A rod 3 of tungsten, tantalum, or molybdenum, is embedded in the body of powdered glass and suitable electrical connections a are arranged at each end of the rod. At the tcp of the tank, a pair of cross rods 5 of similar infusible material are arranged. The reference numeral 3 represents a rod which has been heated and part-ly raised forming a sheet of glass 6. In Figure 2 of the drawings, the apparatus employed is the same las 1n Figure i. In practicing the process, as shown in Figure 2 of the drawings, the rods 3 are arranged at the top of the tank and lowered. The reference numeral 3 repre sents a rod that has been partially lowered, and, thereference numeral 3", a rod that has been lowered to a point near the bottom of the tank. v

Referring to Figure 3 of the'drawings, a source of current 7 is connected to the connections 4 by means of wires 8 and 9. Suitable controlling means,.such as a switch" 10, may be arranged in one of the wires.V The polishing rods 5 are connected to the wire 8 by means of branch wires 11, and

and wire 13. A suitable switch-14 may be arranged in one of the branch wires, or in the 'wire 13,-as shown.

Referring to Figures i and 5 of the drawings, the apparatus therein illustrated com- 195 vprises a hollow plate or table 15, on which the powdered glass is spread. Thev plate is provided with a "-waterspace 16, and with an inlet 17 and an outlet 18, as shown.

In practicing the process, with the appa- 1,110

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sheet of ratus shown in Figures l to 3 o f the drawings, according to the method disclosed in Figure l, the rod 8 is iirst embedded 1n a body of uniformly powdered, finished glass, and the switch l0 closed. Current then passes from the source of current T-through the lead wire 8 and connections 4, to the.

rod 3, and returns to the source through the connection d and lead wire 9. When the rod been heated to the desired temperature, the glass in Jthe immediate vicinity is fused and the rod is then slowly elevated, fusing the powdered Alass into a sheet, as it rises, as indicated at 6. After the 'fusing rod has reached the top oi the body of powdered lglass., it is removed, and the sheet so formed is allowed to cool. Cooling takes place slowly on account of the surrounding body of non-conducting glass powder. The glass so formed has aV slightly roughened surface on both sides and to remove this, it is drawn upwardly between the rods 5, the switch 11i having been closed to complete the circuit and heat the rods A thin slrin is thus melted oli' each side of the sheet as it is removed Jfrom the chamber, and a brilliant surface referred to in the art dre polish is produced. By suitably regulating the speed of fusion or the speed at which the rod 3 is elevated, sheets of any desired thickness may he formed.

ln practicing the process accordiingl to the showing in Figure 2 of the drawings, the rod 3 is first .arranged at the top of the tank and heated. 1When the 'desired temperature to cause fusion oi"- the powdered ,glass is reached, the rod is moved downwardly iusing a sheet in the manner heretofore described. The operation is otherwise the as described inconnection with Figure l of the drawings.= v

lvelcerrinpY to Figures 4 and' 5 of the drawings, when the plate 15 is used, the powdered glass is spread on it to the desired thickness, and it is placed in an oven or other chamber and heated to a temperature sufficiently high to reduce the powdered glass to a plastic or molten condition and fuse it. After the sheet of has 'been fused, it may be cooled in any suitablellmanner, as by subject4 ing it to the temperature of the atmosphere. llater he passed through the space l@ to prevent the zglass from adhering to the surface of the plate. i

is ohvieus that glass of different qualiand having diderent densities and dif- 'erent melting points be spread on the plate in successive layers, and thus the coinplete sheet may be made to have different degrees of harf""ess, toughness, brillianoy, and other quali ies, as desired.

it is to be understood that thI 'orm of my invention herewith shown and described is to he taken as ay preferred example ofv the Liconsa same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, l claim:

l. A method of forming sheet glass which comprises passing a highly heated member through a body oi' powdered, finished glass whereby the powdered glass in the path oi the member is fused, and allowing the fused glass to remain in said body until it cools.

2. method of forming sheet glass which comprises passing a highly heated member through body of powdered, finished glass whereby the powdered glass in the path of the member is fused, allowing the fused glass to cool in said body, and then removingr it.

3. A method of ormin sheet glass which Tyes passing a higlily heated member a body of powdered, finished glass wherecy the powdered glass in the path of the member is fused, allowing the fused glass to cool in said body, and heating the surface 'of the glass to a` fusing temperature while removing. i

4.' An apparatus for forming sheet glass comprising a receptacle adapted to receive a body of powdered, finished glass, a movable member of infusible metal adapted to be embedded in the body of glass within said receptacle, and means for heating said member.

5. An apparatus for forming sheet glass comprising receptacle adapted to receive a bod;v of powdered, finished glass, a` rod of infusible metal adapted to be arranged in said receptacle within said body of glam, means for moving said rod, and means for heating said rod.

6. An apparatus for forming comprisingr a receptacle adapted to receive a body of powdered, finished glass, amovable rod of infusible metal arranged in said receptacle and adapted to be. embedded within the powdered glass, and electrical connections to said rod whereby it may he heated.

'i'. An apparatus for forming sheet glass comprising a receptacle adapted to receive aV body of powdered,`inished glass, a movable member arranged therein, means for heating said member, and av pair ot spaced rods arranged at the top of said tank, said rods being capable of being heated for polishing the sheet glass formed.

ln testimony whereof ailir my in presence of two witnesses.

WLLLAM E. HEAL signature Witnesses:

RUTH Homme, Tiros. PHroirimn.

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